Clinical assessment of disease activity in ulcerative colitis or Crohn's disease is very difficult. Patient symptoms do not necessarily correlate with the inflammatory (disease) activity in the small intestine and colon, leading to educated guesses being used to direct anti-inflammatory therapy. Similar difficulty exists in measuring or testing the efficacy of new therapeutic compounds. Currently the gold standard in diagnosing ulcerative colitis or Crohn's disease is the use of fiberoptic endoscopy coupled with multiple biopsies and pathologic analysis. This very expensive approach requires a skilled specialist and has associated risks, such as risk of sedation, bleeding, and colon perforation. The patient is also subjected to discomfort from the procedure and preparation.
A less invasive and less risky assessment of mucosal disease activity is needed to accurately guide treatment and to provide an objective measure of mucosal injury, both for patients and for use in clinical studies. There is also a need for a simple test to aid in the differentiation of chronic inflammatory disease (UC or CD) from common acute inflammatory disorders or common non-inflammatory benign disorders. There is a further need for a simple method for the differentiation of ulcerative colitis and Crohn's disease because the surgical and medical management for these two diseases is profoundly different.